1. Field of the Invention
The invention relates to network devices and computers executing virtual machines.
2. Description of the Related Art
A revolution is well underway in the data center, namely the conversion from single purpose servers to servers executing a series of virtual machines (VMs), each virtual machine then acting as the previous single purpose server. This virtual machine model allows much better use of the server hardware resources than the prior single use model. The virtual machines are managed using a virtual machine manager. The virtual machine manager can monitor the loading of each physical server and migrate virtual machines between physical servers to address overload conditions. While this may be very helpful when managing the physical server hardware, no consideration is made regarding the underlying physical network infrastructure. VMs are migrated only based on server hardware loading and not network constraints. As a result, it is not unusual to end up with excessive bandwidth consumption and traffic high latency within an L2/L3 router-switch stack, or router-switch virtual chassis cluster, due to high volume transit traffic between physical servers that are connected to different devices within the stack or cluster. As a result, the performance of the VMs may actually be degraded, as compared to the original configuration and definitely is suboptimal.